AOU：Pycnocline (750 m) and deep layer (3000 m)

This is a distribution map of apparent oxygen consumption (AOU) at depths of 750m and 3000m in the entire ocean. Roughly speaking, there is an inverse relationship with the global distribution of oxygen concentration.

　Let's confirm that in the pycnocline (750 m), the AOU is larger in the mid-latitudes of the eastern Atlantic compared to the surrounding area, and that the AOU is smaller south of the Japanese archipelago in the northwestern Pacific. (The reason for this was explained in the section about the global distribution of oxygen.) A somewhat high AOU can also be seen in the Southern Ocean. This is probably due to the high AOU water in the deep layer being brought to a depth of 750 m by vertical mixing. (Currently just a guess)

　Looking at the AOU distribution of deep water (3000 m), AOU is large in the high latitude region of the North Pacific Ocean, which is the terminal point of deep circulation. There is an inverse relationship with the distribution of oxygen concentration. In particular, the northern Bering Sea has the highest AOU of any ocean in the world. This may simply be due to the fact that the oldest water is rising up into the northern Bering Sea, or in addition, organic matter produced in the surface layer of that area may be transported to the deeper layers, decomposed, and stimulated oxygen consumption.